Select the pokemon that you want to clone. Give it any items needed too. Put it in any of your boxes. Now, go to the GTS. Talk to the lady and enter. Put up a pokemon for trade (NOTE: Try this with a low-level pokemon who doesn't have an important item first). When it takes you to the loading screen, watch the little clock on the bottom-right part of the screen. Count how many times it hits the top, and note where it was when the pokemon was uploaded. Go back to the summary screen, and take out the pokemon. Once again, watch the clock. Most people's clock stops moving between 7.5 and 8 rotations.

Now, put the pokemon that you want to duplicate up for trade. Right before the clock gets to the interval where it changes, turn off the DS. Turn it back on, and load the game. You will probably get the error screen, but don't worry. Continue to load the game, and go back to the GTS. If you performed the glitch correctly, the pokemon will still be up for trade. Take it back, and leave. Now, go to the PC to the left of the counter. Load it up, and check your boxes. If you performed the glitch right, you will have duplicates of the pokemon (and possibly item) that you tried to clone.

If you didn't get it, try, try again. It took me about 13 times to get it. Just keep trying.

NOTE: This glitch is very risky. Several GameFAQs members have reported it to screw up their game. Several other members reported their pokemon being traded before they could get back to it. Though the number is very small (about 3/100 people), it still is a risk. Don't say you haven't been warned. To prevent the second problem from happening, request an evolved pokemon that is level 9 or lower (eg. Infernape). (supplied by: forty-two)

Catching Cresselia: After you beat the elite four, go to Canalave City and go in the house with a sign next to it. Talk to the boy in the bed, then talk to the woman. After you talk to the boy and woman exit the house and talk to the sailor that sails you to Iron island. He will ask you to go to Full Moon Island to get a wing to heal his son. Say yes to him. He will sail you there. Now walk up and to the left is the wing to heal his son get it. Dont leave yet, go to the right and then go up you will then see Cresselia go up to it and it runs away like Mesprit. Now go talk to the sailor and sail back to Canalave. When you get back you will follow him into his house and use the wing on his son. His son will then wake up and talk about a nightmare. You can now resume your adventure and look for Cresselia. You are going to need the pokemon marketing app to find Cresselia. (supplied by: wwewwewwe)

Good Fishing rod: The good rod is on route 209. Talk to a fisherman, say yes and he will give you a good rod. (supplied by: connor.harbuck)

Mystery Gift: This is how to obtain the Mystery Gift in Pokemon Diamond. It is different from the previous games, so pay attention.

1) Go to the Jubilife TV station, located in Jubilife City. 2) Go to the 3rd floor. 3) Talk to the man on the left in the lower room. 4) When he asks you to tell him some words, you tell himll him are "everyone" and "happy". 5) He will then ask you for a second set of words. Tell him "Wi-Fi" and "Connection". This will then unlock the Mystery Gift feature on the main menu.

When you go into it you can recieve your gift 3 ways: -Friend -Wireless -Wi-fi While you won't get a gift from this cheat, just get the option to receive it, but when Pokemon/Gamefreak announces when the mystery event will be, go to "Wi-Fi" and ,if you are lucky, you might receive a mystery gift. This can include rare items, such as the ones needed to get to Arceus, Darkrai, and Shaymin. (supplied by: Ho-Oh2224)

Fashion item: When you are walking your pokemon in Amity Square, you can turn around and talk to your pokemon. Every 200 steps talk to your pokemon and it will be holding an item or an item for your fashion case.(supplied by: #Pokepal#)

Old Pokemons When you have another Pokemon game cartridge inserted into the GBA slot of your Nintendo DS, new Pokemon will appear AFTER YOU HAVE OBTAINED THE NATIONAL DEX. Below are the games that you can plug in, what Pokemon you will get, and where they will be. When you take the cartridge out, those unique Pokemon will disappear. These Pokemon appear in the wild and you must use the Pokeradar to find.

Easter Egg-Haunted Mansion's Ghost Gang: Ever wanted to own a Gengar even you have no friends to trade with you a Haunter? Now you can directly catch one or even a Rotom (Ghost/Electric Type)! Just follow these steps. 1.Go to the Old Chatue between 22:00-04:00.If you cannot play during this time slot, change the time settings of your DS. 2.Put a GBA Pokemon Game(Any versions) in the 2nd slot and go inside. (For Gengar go to Step 3, For Rotom go to Step 4 ) 3. After making sure there is a GBA Pokemon Game in your slot 2, you may capture Gengar in the room with red eyes potrait. Huanter may appear there too. 4. Go to the room with the TV and talk to it. Press yes and a Rotom will appear and battle you. It's only Lv15, and there's only 1 in the world game, so be sure to save before you talk to the TV. (supplied by: PokeFan5B)

How to catch Regigigas: First, you need to have the national pokedex, this is obtained by seeing (not catching) all 150 sinnoh pokedex pokemon. Second, you must have access to snowpoint temple in snowpoint city (if you have the national pokedex, this shouldn't be a problem). And third, you need to have regice, registeel, and regirock, which can only be obtained through pal park from the ruby/sapphire/emerald games or by using a cheating device. If you have met all these conditions (make sure to have regice, registeel and regirock in your party), then navigate the snowpoint temple (just a sliding puzzle with ice, a pokemon staple) and regigigas will be waiting for you at the bottom floor. He will be at level 70, and he will have the ability "slow start" (his atk. and speed are cut in half for 5 turns). Make sure to hit him hard and fast before the five turns are up. Try to paralyze regigigas and catch him with an ultra ball, you'll want to save your master ball for another pokemon that runs, like mespirit or cresslia. (supplied by: Latiosmaster47)

Clone Pokemon: To clone pokemon without wi-fi put a ditto in the daycare and send the pokemon you wanna clone to the day care too. (it works on all pokemon with GENDERS except legendaries) even if the pokemon dont like each other they'll still lay an egg. What ever pokemon you put in the day care with ditto the unevolved form (or the same pokemon) will hatch from the egg. (supplied by: wolverine9900)

Get Lucario: Fly to Canalave city and sail to iron island. Go through the cave and on your first time you will team up with Riley. Battle some people and team galactic and after he will give you an egg. in the egg will be Riolu. Get Riolu on a high friendship and level up between 4am and 8pm and you will have lucario. (supplied by: hobo7117)

How to catch cresselia/mesprit: If you have cresselia and mesprit running around sinnoh, this is for you. First, migrate wobblefett from leaf green, fire red, ruby, saphire, or emerald. Next go to tunback cave and catch brongzong. Then find either mesprit or cresselia. Have wobblefett out first no matter what level. His ability should hold the pokemon in battle. Weaken the opposing pokemon. Switch wobblefett with brongzong. Use block. Bronzong should know it. Then use an ultra ball. It should catch it. If it doesn't, keep trying. Make sure it's health is low. Then capture it. (supplied by: omega110)

LOL! Hey, just to let EVERYONE know that reads this post, I have quit my diamond game because it's too hard even WITH my action replay because it won't work. I'll still post here, but I did the same on the pearl page becuase the same happened with pearl. I'll mostly be on platinum page, though.